1. Field of the Invention
The present invention relates to a communication apparatus and method, and a storage medium.
2. Description of the Related Art
Conventionally, a remote system using a plurality of cameras includes a plurality of video cameras, and a synthesizer for performing analog synthesis of the images output from these cameras. Such a system is typically utilized within a relatively small building, and is called a local monitoring system. In contrast to such local monitoring systems, remote monitoring systems have been proposed in which a plurality of cameras are connected to a digital network, such as a LAN (local area network), an ISDN (integrated services digital network), or the like, serving as a public digital network, in order to provide a more flexible system and to connect a larger number of cameras which are present at more remote locations.
In some recent remote monitoring systems, a personal computer or a work station is utilized as a monitoring terminal, and image display using a graphical user interface (GUI), and system control are realized. By utilizing the GUI of the computer as the monitoring terminal, even a person who is not familiar with the apparatus can easily operate the system. In particular, by displaying a control panel of a camera which outputs an image, on a monitor together with an image from the camera, the operability of the system can be improved.
For example, a summary of images from a plurality of cameras, or the details of an image from a specific camera, may be displayed as an image in the conventional system of this type. However, the operability of the display operation and the capability to identify the state of the system are not always acceptable. Therefore, there is room for improvement.
Consider a case in which images from a plurality of cameras are displayed and the processing speed of the monitoring terminal is not high.
The monitoring terminal sequentially expands and displays received compressed images from a plurality of cameras. However, when the calculation speed of the monitoring terminal is not high, the frame rate of the displayed image from each camera is, in some cases, reduced. Furthermore, when the network does not have a sufficient capacity for the transmitted image or images, the frame rate is also reduced.
As a result of frame rate reduction, the operator of such a conventional monitoring system may erroneously recognize that there is an abnormality in the monitoring terminal because a change in the displayed image is small. In another case, even if there is no change in the displayed image because there is an abnormality in the monitoring terminal, the operator may not recognize the abnormality and fail to correctly monitor the image.
This problem arises not only when the number of cameras is large, but also when the resolution of the image received from each camera is high although the number of cameras is small.